The interrelationship of a structurally and metabolically related class of glycer olipids will be studied. They include, in addition to the CDP-diglycerides, the inositol phospholipids (phosphatidylinositol and the polyphosphoinositides), phosphatidate and diglycerides, particularly those species enriched in 1-stearoyl,2-arachidonoyl substituents. Emphasis is directed toward elucidation of membrane components that play a role in neural function. The turnover of these lipids is implicated on the basis of previous studies in the events that follow acetylcholine action at the muscarinic synapse. These studies have relevance to a number of neurological disorders in which inositol or arachidonate and the prostaglandins play a role.